The invention relates to an electrosurgical instrument.
In high-frequency surgery (HF surgery), alternating current is conducted at high frequency through the human body in order to damage or cut tissue in a targeted manner. An essential advantage over conventional cutting techniques with a scalpel is that, simultaneous with the cutting, suppression of bleeding can take place by closing the affected vessels (coagulation). A distinction is made between a high-frequency generator, which generates the relevant alternating current, and the electrosurgical instrument by means of which the current is applied to the tissue. The electrosurgical instruments which are frequently used are electrosurgical scissors and electrosurgical clamps. These instruments perform a certain double function, since they provide both conventional mechanical clamping and cutting and electrical coagulation and cutting by means of the high-frequency currents.
The electrosurgical instruments described above belong to the class of bipolar electrosurgical instruments. The tool heads of the relevant instruments have two poles between which the alternating current flows. Taking the example of electrosurgical scissors, a first blade can be supplied with the current in a manner that is electrically separated from a second blade. The circuit is completed between the two blades by the tissue to be cut. In order to ensure good functioning of these bipolar electrosurgical instruments, reliable insulation of the electrical conducting paths in the corresponding electrosurgical instruments is necessary. In this regard, the mechanical joints of conventional electrosurgical instruments prove to be particularly problematic since crossing-over and contacting of the relevant conducting paths occurs at the mechanical joints.
The electrosurgical instruments described above are sufficiently well known from U.S. Pat. No. 6,406,475 B1 and U.S. Pat. No. 5,324,289. In order to separate the respective conducting paths from one another, it is proposed therein that insulation be provided at the mechanical joints. For reliable insulation of the two conducting paths, high demands are placed on the form of insulation, which consequently makes production complex and expensive.
A further disadvantage of known electrosurgical instruments is that process-controlled production of a large product range is very complex and expensive. It may be, for example, that different surgeons place different demands on the associated handles of essentially the same instrument on account of the differing anatomy of their hands.
In light of this prior art, it is an object of the present invention to develop an electrosurgical instrument such that it can be operated reliably and practically and that it can be produced economically and efficiently.